Containers: implement arbitrary array insertion.

Not the most efficient implementation yet -- it's quite a lot of new
logic to make it efficient, so doing it gradually instead. See the TODOs
in the code.

doc/corrade-changelog.dox

@@ -84,6 +84,8 @@ namespace Corrade {
 -   New @ref Containers::ArrayView2, @ref Containers::ArrayView3 and
     @ref Containers::ArrayView4 convenience aliases for
     @ref Containers::StaticArrayView
+-   Added a family of @ref Containers::arrayInsert() functions for arbitrary
+    insertion into growable arrays
 
 @subsubsection corrade-changelog-latest-new-pluginmanager PluginManager library
 

src/Corrade/Containers/Array.h

@@ -175,11 +175,11 @@ custom allocators, type constructibility and such.
 
 As long as the type stored in the array is nothrow-move-constructible, any
 @ref Array instance can be converted to a growing container by calling the
-family of @ref arrayAppend(), @ref arrayReserve(), @ref arrayResize() ...
-functions. A growable array behaves the same as a regular array to its
-consumers --- its @ref size() returns the count of *real* elements, while
-available capacity can be queried through @ref arrayCapacity(). Example of
-populating an array with an undetermined amount of elements:
+family of @ref arrayAppend(), @ref arrayInsert(), @ref arrayReserve(),
+@ref arrayResize() ... functions. A growable array behaves the same as a
+regular array to its consumers --- its @ref size() returns the count of *real*
+elements, while available capacity can be queried through @ref arrayCapacity().
+Example of populating an array with an undetermined amount of elements:
 
 @snippet Containers.cpp Array-growable